BUSINESS OPTIMIZATION CHARGES - Summary of Business Optimization Charges (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 32	$ 26	$ 67	$ 58
Business Optimization Programs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	32	26	67	58
Costs to implement business optimization programs	4	6	14	19
Total business optimization charges	$ 36	$ 32	$ 81	$ 77

Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

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